Gas cooking appliances with a glass or glass-ceramic plate as a cooking surface are marketed in two versions. In one version, gas-radiation burners in which the gas that is fed in together with primary air is burned at the surface of a burner plate that is made of porous ceramic are provided for heating. One or more of such gas-radiation burners are arranged at a distance under a common glass-ceramic plate, which is glued in place in a cooking area frame. Here, each gas-radiation burner defines a cooking zone on the top side of the glass-ceramic plate. Below the glass-ceramic plate is also an insulating part that has recesses for the gas-radiation burner and exhaust air ducts for discharging hot exhaust gases from the individual burners, which end in a common elongated outlet that lies below the cooking area frame, which in this area has lattice-like ventilation slots for the discharge of hot exhaust air.
A gas cooking appliance of this version is described in DE 43 26 945 C2, incorporated herein by reference. This known gas cooking appliance has a fan that brings in air from the outside to the burner and in addition cools the exhaust gases via a bypass, as well as preventing elevated temperatures in the housing wall by a ventilation system that is installed on the outside walls, but the design of the exhaust air guideway requires that the hot exhaust gases first flow past the connecting point between the glass-ceramic plate and cooking area frame and only then be further mixed with cold air and pass through the outlet openings into the ventilation lattice. This leads to considerable thermal stress on the adhesive compound that is between the glass-ceramic plate and the cooking area frame and that also must be present in the area of the ventilation lattice for overflow protection. Baffles or the like could reduce the thermal stress, but this would result in additional installation expense.
It is judged a further drawback that ventilation lattices are not especially easy to clean, tend to discolor, and also detract from the overall appearance of the gas cooking appliance.
In the second version of gas cooking appliances with a glass or glass-ceramic plate as a cooking surface, atmospheric burners, i.e., burners with open flames, are integrated in corresponding openings in the glass or glass-ceramic plate. While in the first version with gas-radiation burners the exhaust air requires a special guideway, the second version with atmospheric burners depends on a supply of primary air, i.e., fresh air. In upright ranges according to the second version, primary air is supplied in a known way via ventilation slots, i.e., via corresponding ventilation lattices in the range or counter guard area. This concept has the drawback that the ventilation lattices are problematical with respect to cleaning, as already mentioned above. In the case of recessed cooking areas according to the second version, as, for example, DE 195 05 469 C1, incorporated herein by reference, has disclosed, however, supplying primary air via corresponding recesses in the bottom plate is at the least not readily possible. Therefore, in the known case on the cooking surface plane, i.e., either between the glass-ceramic plate and the associated frame structure or the bent control panel, an elongated opening is provided for the air supply, which is covered in the shape of a hood. This design of the primary air supply has the drawback that only a relatively small overflow volume can be collected, so that there exists the danger that spilled food may pass through the fresh air intake opening into the interior of the recess and contaminate the electronic/electric components that are contained within. Even in the case where the cooking surface is maintained and cleaned, however, the danger of the entry of liquids, e.g., cleaning materials, exists, with the corresponding adverse consequences.